(as in the chain rather than Cortland Greenspot 130 pound braided Dacron
trolling line)
The G forces required to break your carabiner will destroy your glider and
kill you more than six and three times over respectively.
Steel carabiners don't break and I've never heard of a safety link between
the harness suspension and the parachute bridle saving anyone's life.
I've also never heard of the failure of a properly constructed and installed
hang loop or strap and my backup is another useless piece o' crap no longer
dangling in the breeze.
I think these ideas sounded good thirty years ago and we continue to do them
because that's the way we do them rather than because of any actual safety
enhancement.
Very sorry to hear of this latest trauma of the sort about which we do need
to be concerned.
weak links
Moderator: CHGPA BOD
weak links
Consider having heard.? My primary hang loop broke in Guatemala.? It had been installed by Ole Olson the day before (we were changing gliders almost everyday) when I had flown the same glider (K-2 - like the one I'd been flying for over 2 years). THe gliders he'd leased from PacAir were new in November and this was?later in the winter. I've never heard of another hang loop breaking.
Christy
TadErcksn@aol.com wrote:
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Christy
TadErcksn@aol.com wrote:
__________________________________________________I've also never heard of the failure of a properly constructed and installed
hang loop or strap and my backup is another useless piece o' crap no longer
dangling in the breeze.
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Biners
Tad,
It's not so much the concern of a steel biner breaking in flight. It's the possibility of the gate opening. I've seen several photos where pilots are flying and the weight is suspended on the gate of the biner. There was a recent pic of a paraglider in flight with the gate wedged open. And in the case of Bo's accident last year, there would have probably been a far different result had the parachute been separately attached to the harness main as a back-up with a climbing screw gate, i.e. the chute would have been attached to Bo when he threw it.
Matthew
It's not so much the concern of a steel biner breaking in flight. It's the possibility of the gate opening. I've seen several photos where pilots are flying and the weight is suspended on the gate of the biner. There was a recent pic of a paraglider in flight with the gate wedged open. And in the case of Bo's accident last year, there would have probably been a far different result had the parachute been separately attached to the harness main as a back-up with a climbing screw gate, i.e. the chute would have been attached to Bo when he threw it.
Matthew
-
Tad Eareckson
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
weak links
Thanks for the feedback, Christy and Matthew.
Naw, I know about that one (Guatemala), think about it a lot, and had it
foremost in mind when I wrote. We're never gonna know what happened 'cause the
evidence disappeared into the hillside never to be seen again. I don't know how
the K2 was configured but properly stitched one inch flat nylon webbing
doesn't just fall apart. There had to be a big problem with fabrication or
installation.
My strap assembly is bolted to the kingpost and I do have a backup of sorts -
I stitched a short length of webbing to join the ends above the keel to guard
against a hardware failure but I have as much confidence in the main
component as anything else up there.
There is no reason that we should be worried about gate and minor axis
problems with respect to carabiners.
Check out Omega Pacific's 7/16" Steel Modified D
(http://www.omegapac.com/op_rescue_716modsteeld.html) Quik-Lok models - OP76S35Q and OP76S38Q and, if you
must, OP76S383Q. The captive eye feature looks like a useful idea for our
purposes but the pin installation is one-time/nonreversible/permanent. If you
hear a click the gate is locked and will stay that way until you tell it
otherwise.
I got out the needle and thread and reduced the eye of the harness suspension
such that it offers a lot of resistance but installation is not a headache.
There is no way the carabiner will rotate out of major axis orientation in
flight.
While it's very unfortunate that some of the equipment involved in our
pursuits gives no overt indication of being amiss and can even present an illusion
of being intact, Bo's problem wasn't that he didn't have a backup - he didn't
have a primary.
Naw, I know about that one (Guatemala), think about it a lot, and had it
foremost in mind when I wrote. We're never gonna know what happened 'cause the
evidence disappeared into the hillside never to be seen again. I don't know how
the K2 was configured but properly stitched one inch flat nylon webbing
doesn't just fall apart. There had to be a big problem with fabrication or
installation.
My strap assembly is bolted to the kingpost and I do have a backup of sorts -
I stitched a short length of webbing to join the ends above the keel to guard
against a hardware failure but I have as much confidence in the main
component as anything else up there.
There is no reason that we should be worried about gate and minor axis
problems with respect to carabiners.
Check out Omega Pacific's 7/16" Steel Modified D
(http://www.omegapac.com/op_rescue_716modsteeld.html) Quik-Lok models - OP76S35Q and OP76S38Q and, if you
must, OP76S383Q. The captive eye feature looks like a useful idea for our
purposes but the pin installation is one-time/nonreversible/permanent. If you
hear a click the gate is locked and will stay that way until you tell it
otherwise.
I got out the needle and thread and reduced the eye of the harness suspension
such that it offers a lot of resistance but installation is not a headache.
There is no way the carabiner will rotate out of major axis orientation in
flight.
While it's very unfortunate that some of the equipment involved in our
pursuits gives no overt indication of being amiss and can even present an illusion
of being intact, Bo's problem wasn't that he didn't have a backup - he didn't
have a primary.
-
Tad Eareckson
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
weak links
I stand partially corrected. Memory and logic failed. If the loop went into
the carabiner and wasn't there later then, yeah, an installation problem can
be ruled out and the evidence points strongly towards someone asleep at the
sewing machine. I'll truncate the last sentence of Paragraph 2 to read, "There
had to be a big problem with fabrication."
I'm very happy that on that occasion you were flying with a backup but it's
too bad that the evidence was lost 'cause somebody should have been stood up
against a wall. And if the backup came from the same shop as the primary it's a
good thing that it was way too long and you were compelled to climb into the
control frame.
My point remains intact however - we have to be able to trust the materials
which are keeping us alive up there. Nylon webbing and stitching strengths are
reliable, quantifiable, and FAA specable. If they weren't skydiving would
tend to be an extremely unpopular one-time-only sort of sport.
The material and fabrication between the suspension point and the carabiner
is pretty much the same as that between the carabiner and the pod. Why bother
backing up one and not the other?
the carabiner and wasn't there later then, yeah, an installation problem can
be ruled out and the evidence points strongly towards someone asleep at the
sewing machine. I'll truncate the last sentence of Paragraph 2 to read, "There
had to be a big problem with fabrication."
I'm very happy that on that occasion you were flying with a backup but it's
too bad that the evidence was lost 'cause somebody should have been stood up
against a wall. And if the backup came from the same shop as the primary it's a
good thing that it was way too long and you were compelled to climb into the
control frame.
My point remains intact however - we have to be able to trust the materials
which are keeping us alive up there. Nylon webbing and stitching strengths are
reliable, quantifiable, and FAA specable. If they weren't skydiving would
tend to be an extremely unpopular one-time-only sort of sport.
The material and fabrication between the suspension point and the carabiner
is pretty much the same as that between the carabiner and the pod. Why bother
backing up one and not the other?
weak links
-----Original Message-----
From: TadErcksn@aol.com [mailto:TadErcksn@aol.com]
>The material and fabrication between the suspension point and the carabiner
>is pretty much the same as that between the carabiner and the pod. Why
>bother
>backing up one and not the other?
Because the primary hang strap is subject to wear and dependant on hardware
in some applications. Think rocker arm.
Kev C
From: TadErcksn@aol.com [mailto:TadErcksn@aol.com]
>The material and fabrication between the suspension point and the carabiner
>is pretty much the same as that between the carabiner and the pod. Why
>bother
>backing up one and not the other?
Because the primary hang strap is subject to wear and dependant on hardware
in some applications. Think rocker arm.
Kev C
weak links
I seem to remember Richard Hays has a story about pulling off what looked
like a perfectly good hangstrap and finding it halfway worn through on the
inside. I think many of us are terrible at preventitive maintenance. Keep
the backup hangstrap.
Brian Vant-Hull
301-646-1149
>
> Because the primary hang strap is subject to wear and dependant on hardware
> in some applications. Think rocker arm.
>
> Kev C
>
like a perfectly good hangstrap and finding it halfway worn through on the
inside. I think many of us are terrible at preventitive maintenance. Keep
the backup hangstrap.
Brian Vant-Hull
301-646-1149
>
> Because the primary hang strap is subject to wear and dependant on hardware
> in some applications. Think rocker arm.
>
> Kev C
>
weak links
What do people think of the "integrated" primary and back-up from Wills
(that's what comes on the U2)? - Hugh
On 2 Jun 2005, at 09:55, Vant-Hull - Brian wrote:
>
>
> I seem to remember Richard Hays has a story about pulling off what
> looked
> like a perfectly good hangstrap and finding it halfway worn through on
> the
> inside. I think many of us are terrible at preventitive maintenance.
> Keep
> the backup hangstrap.
>
> Brian Vant-Hull
> 301-646-1149
>
>>
>> Because the primary hang strap is subject to wear and dependant on
>> hardware
>> in some applications. Think rocker arm.
>>
>> Kev C
>>
>
>
>
(that's what comes on the U2)? - Hugh
On 2 Jun 2005, at 09:55, Vant-Hull - Brian wrote:
>
>
> I seem to remember Richard Hays has a story about pulling off what
> looked
> like a perfectly good hangstrap and finding it halfway worn through on
> the
> inside. I think many of us are terrible at preventitive maintenance.
> Keep
> the backup hangstrap.
>
> Brian Vant-Hull
> 301-646-1149
>
>>
>> Because the primary hang strap is subject to wear and dependant on
>> hardware
>> in some applications. Think rocker arm.
>>
>> Kev C
>>
>
>
>
-
Tad Eareckson
- Posts: 304
- Joined: Wed Feb 09, 2005 8:50 am
weak links
After something on the order of three decades of evolution we're finally
getting serious about getting stuff out of the airflow that doesn't need to be
there.
The carabiner was a nice place to attach a parachute bridle but that left a
lot of extra material bouncing molecules out of the way. One of the earlier
alternate design experimenters found himself in need of a deployment and gently
descended under a full canopy dead from a broken neck as the attachment point
had been relocated to that critical. And we all know about Bo. But I think
there are ways to address problems that don't involve slowing us back down.
I'm guessing that a half chewed through hang loop was fashioned out of
tubular nylon and mounted on the keel over a glued on no-skid strip. And I'm rather
certain that the owner had an underdeveloped concept of the philosophy of
preflight inspection.
If there are indeed remaining wear problems associated with hardware
connections I think we need to go back to the drawing board. I am, probably without
justification, more nervous about the metal than the fiber but eventually
figured out I didn't need to guard against cracks by running an additional five ton
capacity length of webbing the whole way around. All I needed to do was span
a short piece above the keel and out of the airflow.
An integrated backup is a reasonable alternative but I'm still waiting to
hear of one to be loaded.
getting serious about getting stuff out of the airflow that doesn't need to be
there.
The carabiner was a nice place to attach a parachute bridle but that left a
lot of extra material bouncing molecules out of the way. One of the earlier
alternate design experimenters found himself in need of a deployment and gently
descended under a full canopy dead from a broken neck as the attachment point
had been relocated to that critical. And we all know about Bo. But I think
there are ways to address problems that don't involve slowing us back down.
I'm guessing that a half chewed through hang loop was fashioned out of
tubular nylon and mounted on the keel over a glued on no-skid strip. And I'm rather
certain that the owner had an underdeveloped concept of the philosophy of
preflight inspection.
If there are indeed remaining wear problems associated with hardware
connections I think we need to go back to the drawing board. I am, probably without
justification, more nervous about the metal than the fiber but eventually
figured out I didn't need to guard against cracks by running an additional five ton
capacity length of webbing the whole way around. All I needed to do was span
a short piece above the keel and out of the airflow.
An integrated backup is a reasonable alternative but I'm still waiting to
hear of one to be loaded.